/*
 * decorate-core.c
 *
 * Part of gwm, the Gratuitous Window Manager,
 *     by Gary Wong, <gtw@gnu.org>.
 *
 * Copyright (C) 2009  Gary Wong
 *
 *  This program is free software: you can redistribute it and/or modify
 *  it under the terms of version 3 of the GNU General Public License as
 *  published by the Free Software Foundation.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 * $Id$
 */

#include <config.h>

#include <assert.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <xcb/xcb.h>

#include "gwm.h"

#include "button.h"
#include "decorate-core.h"
#include "frame.h"
#include "utf8.h"

#define FONT_SIZE 12
#define STRING2(x) #x
#define STRING(x) STRING2(x)
#define FONT_SIZE_STRING STRING( FONT_SIZE )

#define FEEDBACK_WIDTH 96 /* width of size feedback window */
#define FEEDBACK_HEIGHT 24 /* height of size feedback window */

static xcb_font_t font;
static xcb_gcontext_t *gcs;

static int digit_widths[ 11 ]; /* widths of characters '0' to '9', and 'x' */
static unsigned int width_sequence, cmap_sequence;

static xcb_void_cookie_t core_text( xcb_drawable_t drawable, int screen, 
				    int col, int x, int y, const char *text ) {

    int i, len;
    const unsigned char *p;
    uint8_t *param, *out;
    uint32_t g, n;
    
    len = 0;
    if( text ) {
	p = (const unsigned char *) text;
	while( ( g = utf8_next( &p ) ) )
	    if( g < 0x10000 )
		len++;
    }

    if( len ) {
	n = gwm_screens[ screen ].pixels[ col ];
	xcb_change_gc( c, gcs[ screen ], XCB_GC_FOREGROUND, &n );

	out = param = alloca( ( len + ( len >> 7 ) + 1 ) << 1 );

	for( p = (const unsigned char *) text, i = 0; i < len;
	     i++, out += 2 ) {
	    if( !( i & 0x7F ) ) {
		out[ 0 ] = len - i > 0x7F ? 0x80 : len - i; /* length */
		out[ 1 ] = 0; /* delta */
		out += 2;
	    }

	    while( assert( *p ), ( g = utf8_next( &p ) ) > 0xFFFF )
		;

	    out[ 0 ] = g >> 8;
	    out[ 1 ] = g & 0xFF;
	}

	return xcb_poly_text_16( c, drawable, gcs[ screen ], x, y, out - param,
				 param );
    } else {
	xcb_void_cookie_t r = { 0 };

	return r;
    }
}
	
extern void core_update_window( struct gwm_window *window ) {

    if( window->type == WINDOW_CHILDLESS )
	return;

    if( !window->cleared )
	xcb_clear_area( c, FALSE, window->w, window->update.x, window->update.y,
			window->update.width, window->update.height );

    xcb_set_clip_rectangles( c, XCB_CLIP_ORDERING_YX_BANDED,
			     gcs[ window->screen ], 0, 0, 1, &window->update );

    if( window->type == WINDOW_FRAME ) {
	char *name = window->u.frame.child->u.managed.name;

	core_text( window->w, window->screen, window == focus_frame ?
		   COL_TITLE_ACTIVE : COL_TITLE_INACTIVE,
		   button_size( window->u.frame.button, TRUE ) + 4,
		   FONT_SIZE, name ? name : "(Untitled)" );
    } else if( window->type == WINDOW_MENUITEM ) {
	struct gwm_window *menu = window->u.menuitem.menu;

	core_text( window->w, window->screen,
		   menu->u.menu.active_item >= 0 &&
		   menu->u.menu.items[ menu->u.menu.active_item ] == window ?
		   COL_MENU_ACTIVE_FORE : COL_MENU_INACTIVE_FORE,
		   4, FONT_SIZE, window->u.menuitem.label );
    } else if( window->type == WINDOW_FEEDBACK ) {
	char *p, text[ 32 ];
	int width;
	
	if( width_sequence ) {
	    sync_with_callback( width_sequence );
	    width_sequence = 0;
	}

	sprintf( text, "%dx%d", window->u.feedback.fb_width,
		 window->u.feedback.fb_height );

	for( width = 0, p = text; *p; p++ )
	    if( *p >= '0' && *p <= '9' )
		width += digit_widths[ *p - '0' ];
	    else
		width += digit_widths[ 10 ];

	core_text( window->w, window->screen, COL_FEEDBACK_FORE,
		   ( FEEDBACK_WIDTH - width ) >> 1, 16, text );
    }
}

extern void core_window_size( struct gwm_window *window, int *width,
			      int *height ) {

    switch( window->type ) {
    case WINDOW_MENUITEM:
	if( window->u.menuitem.label ) {
	    *width = FONT_SIZE * utf8_length( (const unsigned char *)
					      window->u.menuitem.label );
	    *height = FONT_SIZE + 4;
	} else {
	    *width = 8;
	    *height = 4;
	}
	return;
	
    case WINDOW_FEEDBACK:
	*width = FEEDBACK_WIDTH;
	*height = FEEDBACK_HEIGHT;
	return;
	
    default:
	assert( FALSE );
    }
}

extern void core_replace_icons( struct gwm_window *window, int num_icons,
				int *widths, int *heights, uint32_t **icons,
				xcb_pixmap_t *bitmaps ) {

    /* FIXME Implement core icons... or maybe not. */
}

static void query_text_callback( unsigned int sequence, void *reply,
				 xcb_generic_error_t *error,
				 union callback_param p ) {

    xcb_query_text_extents_reply_t *r = reply;

    if( error ) {
	show_error( error );
	
	free( error );
    }

    if( reply ) {
	digit_widths[ p.l ] = r->overall_width;

	free( reply );
    }
}

static const uint16_t decoration_cols[ NUM_COLS ][ 3 ] = {
    { 0x2222, 0x3333, 0xEEEE }, /* COL_FRAME_ACTIVE */
    { 0xAAAA, 0xAAAA, 0xAAAA }, /* COL_FRAME_INACTIVE */
    { 0x0000, 0x0000, 0x0000 }, /* COL_BORDER */
    { 0xFFFF, 0x0000, 0x0000 }, /* COL_BUTTON_ACTIVE */
    { 0xCCCC, 0xCCCC, 0xCCCC }, /* COL_BUTTON_INACTIVE */
    { 0xFFFF, 0xFFFF, 0xFFFF }, /* COL_TITLE_ACTIVE */
    { 0x0000, 0x0000, 0x0000 }, /* COL_TITLE_INACTIVE */
    { 0xFFFF, 0xFFFF, 0xFFFF }, /* COL_FEEDBACK_BACK */
    { 0x0000, 0x0000, 0x0000 }, /* COL_FEEDBACK_FORE */
    { 0x2222, 0x3333, 0xEEEE }, /* COL_MENU_ACTIVE_BACK */
    { 0xFFFF, 0xFFFF, 0xFFFF }, /* COL_MENU_ACTIVE_FORE */
    { 0xCCCC, 0xCCCC, 0xCCCC }, /* COL_MENU_INACTIVE_BACK */
    { 0x0000, 0x0000, 0x0000 }  /* COL_MENU_INACTIVE_FORE */
};

static uint16_t luma( int col ) {

    return ( decoration_cols[ col ][ 0 ] * 0x4C8BU +
	     decoration_cols[ col ][ 1 ] * 0x9646U +
	     decoration_cols[ col ][ 2 ] * 0x1D2FU ) >> 16;
}

static void handle_alloc_color( unsigned int sequence, void *reply,
				xcb_generic_error_t *error,
				union callback_param p ) {
    
    xcb_alloc_color_reply_t *r = reply;
    int screen = p.l >> 16, col = p.l & 0xFFFF;
    
    if( error ) {
	if( error->error_code != XCB_ALLOC )
	    show_error( error );
	
	/* No standard RGB map available, and we couldn't allocate a shared
	   colour.  Fall back to black or white. */
	gwm_screens[ screen ].pixels[ col ] = luma( col ) >= 0x8000 ?
	    screens[ screen ]->white_pixel : screens[ screen ]->black_pixel;

	free( error );
    }

    if( reply ) {
	gwm_screens[ screen ].pixels[ col ] = r->pixel;

	free( reply );
    }
}

static void handle_get_default_map( unsigned int sequence, void *reply,
				    xcb_generic_error_t *error,
				    union callback_param p ) {

    int col, got_cols = FALSE;
    
    if( error ) {
	show_error( error );

	free( error );
    }

    if( reply ) {
	xcb_get_property_reply_t *prop = reply;    
	struct std_cmap {
	    /* RGB_COLOR_MAP property -- see ICCCM 2.0, section 6.4. */
	    xcb_colormap_t colormap;
	    uint32_t red_max, red_mult, green_max, green_mult, blue_max,
		blue_mult, base_pixel;
	    xcb_visualid_t visual_id;
	    uint32_t kill_id;
	} *std_cmaps = xcb_get_property_value( prop );
	int num_cmaps = ( prop->value_len << 2 ) / sizeof *std_cmaps;
	int i;

	if( prop->format == 32 )
	    for( i = 0; i < num_cmaps; i++ )
		if( std_cmaps[ i ].visual_id ==
		    gwm_screens[ p.l ].root_visual->visual_id ) {
		    
		    for( col = 0; col < NUM_COLS; col++ ) {
			int r0, g0, b0, r, g, b;

			if( gwm_screens[ p.l ].root_visual->_class ==
			    XCB_VISUAL_CLASS_STATIC_GRAY ||
			    gwm_screens[ p.l ].root_visual->_class ==
			    XCB_VISUAL_CLASS_GRAY_SCALE ) {
			    r0 = luma( col );
			    g0 = b0 = 0;
			} else {
			    r0 = decoration_cols[ col ][ 0 ];
			    g0 = decoration_cols[ col ][ 1 ];
			    b0 = decoration_cols[ col ][ 2 ];
			}

			r = ( r0 * std_cmaps[ i ].red_max + 0x8000 ) >> 16;
			g = ( g0 * std_cmaps[ i ].green_max + 0x8000 ) >> 16;
			b = ( b0 * std_cmaps[ i ].blue_max + 0x8000 ) >> 16;

			gwm_screens[ p.l ].pixels[ col ] =
			    std_cmaps[ i ].base_pixel +
			    r * std_cmaps[ i ].red_mult +
			    g * std_cmaps[ i ].green_mult +
			    b * std_cmaps[ i ].blue_mult;
		    }

		    got_cols = TRUE;
		    break;
		}

	free( reply );
    }

    if( !got_cols )
	/* No useful default maps found; try allocating directly. */
	for( col = 0; col < NUM_COLS; col++ ) {
	    int r, g, b;
	    union callback_param cp;
	    
	    if( gwm_screens[ p.l ].root_visual->_class ==
		XCB_VISUAL_CLASS_STATIC_GRAY ||
		gwm_screens[ p.l ].root_visual->_class ==
		XCB_VISUAL_CLASS_GRAY_SCALE )
		r = g = b = luma( col );
	    else {
		r = decoration_cols[ col ][ 0 ];
		g = decoration_cols[ col ][ 1 ];
		b = decoration_cols[ col ][ 2 ];
	    }
	    
	    cp.l = ( p.l << 16 ) | col;
	    handle_async_reply( cmap_sequence = xcb_alloc_color(
				    c, screens[ p.l ]->default_colormap,
				    r, g, b ).sequence, handle_alloc_color,
				cp );
	}
}

extern INIT void decorate_core_init( void ) {

    int i;
    uint32_t n;
    const char *font_name = "-*-lucida-bold-r-normal-sans-"
	FONT_SIZE_STRING "-*-*-*-p-*-iso10646-1", /* FIXME allow selection */
	*cursor_font_name = "cursor";
    xcb_char2b_t c2;
    union callback_param p;
    xcb_font_t cursor_font;
    static INITD const int cursor_glyphs[ NUM_CURSORS ] = {
	134, /* CURSOR_TL */
	138, /* CURSOR_T */
	136, /* CURSOR_TR */
	70, /* CURSOR_L */
	52, /* CURSOR_C */
	96, /* CURSOR_R */
	12, /* CURSOR_BL */
	16, /* CURSOR_B */
	14, /* CURSOR_BR */
	68, /* CURSOR_ARROW */
	88 /* CURSOR_DESTROY */
    };

    font = xcb_generate_id( c );
    xcb_open_font( c, font, strlen( font_name ), font_name );
    
    gcs = xmalloc( num_screens * sizeof *gcs );
    
    for( i = 0; i < num_screens; i++ ) {
	gcs[ i ] = xcb_generate_id( c );
	n = font;
	xcb_create_gc( c, gcs[ i ], screens[ i ]->root, XCB_GC_FONT, &n );
    }

    c2.byte1 = 0;
    for( p.l = 0; p.l <= 9; p.l++ ) {
	c2.byte2 = p.l + '0';
	handle_async_reply( xcb_query_text_extents( c, font, 1, &c2 ).sequence,
			    query_text_callback, p );
    }
    c2.byte2 = 'x';
    handle_async_reply( width_sequence =
			xcb_query_text_extents( c, font, 1, &c2 ).sequence,
			query_text_callback, p );

    cursor_font = xcb_generate_id( c );
    xcb_open_font( c, cursor_font, strlen( cursor_font_name ),
		   cursor_font_name );
    for( i = 0; i < NUM_CURSORS; i++ ) {
	cursors[ i ] = xcb_generate_id( c );
	xcb_create_glyph_cursor( c, cursors[ i ], cursor_font, cursor_font,
				 cursor_glyphs[ i ], cursor_glyphs[ i ] | 1,
				 0, 0, 0, 0xFFFF, 0xFFFF, 0xFFFF );
    }
    xcb_close_font( c, cursor_font );

    /* Retrieve any RGB_DEFAULT_MAP properties on the roots. */
    for( i = 0; i < num_screens; i++ ) {
	union callback_param cp;

	cp.l = i;
	handle_async_reply( cmap_sequence =
			    xcb_get_property( c, FALSE, screens[ i ]->root,
					      RGB_DEFAULT_MAP, RGB_COLOR_MAP,
					      0, 0x10000 ).sequence,
			    handle_get_default_map, cp );
    }
}

extern void decorate_core_done( void ) {

#if DEBUG
    free( gcs );
#endif
}